1. Field of the Invention
This invention relates to an improved process for the coproduction of morpholine and 2-(2-hydroxyethoxy)ethyl amine from diethylene glycol. More particularly, this invention relates to a process for the catalytic reductive amination of diethylene glycol for the coproduction of morpholine and 2-(2-hydroxyethoxy)ethyl amine wherein the catalyst that is used consists of cobalt, copper and ceria and/or thoria whereby an enhanced yield of 2-(2-hydroxyethoxy)ethyl amine is obtained.
2. Prior Art
It has heretofore been proposed to prepare morpholine from diethylene glycol by reductive aminolysis as shown, for example by Moss U.S. Pat. No. 3,151,112 which is specifically directed to such a process and Moss U.S. Pat. No. 3,152,998, Habermann U.S. Pat. No. 4,153,581 and British Pat. No. 1,361,363 which disclose reductive amination processes wherein diethylene glycol is mentioned as a feed component.
Another relevant patent is Bedoit U.S. Pat. No. 3,155,657 which is also directed to the coproduction of morpholine and 2-(2-hydroxyethoxy)ethyl amine.
As exemplified by these patents, a wide variety of metals and metal oxides have been proposed for use as catalysts in the reductive amination of feedstocks containing one or more hydroxy groups.
Also, as exemplified by the prior art mentioned above, each particular catalyst system can be characterized as having a unique product distribution for the feedstock with which it is employed. Changes in product distribution, and hence, product selectivity, can normally be accomplished only within comparitively narrow limits.
Morpholine is an article of commerce which is widely used in the preparation of accelerators for curing rubber, optical brighteners for fabrics, etc.
2-(2-Hydroxyethoxy)ethyl amine, which is sold commercially, for example by Texaco Inc., under the trademark DIGLYCOLAMINE.RTM., is also an article of commerce useful for a variety of purposes such as the sweeting of sour natural gas, the treatment of transformer paper, etc.
When morpholine is manufactured as taught by Moss U.S. Pat. No. 3,151,112, one of the coproducts that is formed is 2-(2-hydroxyethoxy)ethyl amine. However, for any specific conversion of diethylene glycol, there is only a comparitively narrow limit within which the ratio of morpholine to 2-(2-hydroxyethoxy)ethyl amine can be varied.
Accordingly, there is a need for a process wherein relatively greater amounts of 2-(2-hydroxyethoxy)ethyl amine can be prepared from a given quantity of feedstock when market conditions so demand.